#百分制成绩转换成等级
score = float(input('请输入成绩: '))
if score >= 90:
    grade = 'A'
elif 80 <= score <90:
    grade = 'B'
elif 70 <= score <80:
    grade = 'C'
elif 60 <= score <70:
    grade = 'D'
else:
    grade = 'E'
print(f'{grade = }')